Thread-trimming mechanism for buttonhole sewing machines



Nav. 10, 1942. E. P. SPAINE #2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 21, 1940 1l Shet `s-Sheet 1 grwMwo/o award @,jain@ wm am E. P.SPAINE Nov. 10, 1942.

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 2l, 1940 11 Sheets-Sheet 2 (giward ,Dm/free NV-A10, l942- E. P.sPAlNE 2,301,798.

THREAD-THINKING IIECHANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 2l, 1940 11 Sheets-Sheet 3 Nov. l0, 1942. E, P. sPAlNE 2,301,798

'. -THREAD-TRIMING MECHANISM FOR BU'IITONHOLE SEWING MACHINES OriginalFiled Sept. 21, 1340 i 11 Sheets-Sheet 4 Nov. 10, 1942. E. P. sPAlNE2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 2 1, 1940 ll Sheets-Sheet 5 @ward /gaz'fzei 95 LQM @www Nov. 10,1942.

E. P sPAlNE THREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINESOriginal Filed Sept. 2l, 1940 1l Sheets-Sheet 6 Se im ward g3,

Noi. l0, 1942. E. P. sPAlNE i l 2,301,798

THREAD-TRIMMING MECHANISM FOR BUTTONHGLE. SEWING MACHINES Original FiledSept. 21, 1940 ll Sheets-Sheet 7 l ik MM @D @am @M Q 7M Citta/meg.

NOV- 10, 1942. E. P. sPAlNE 2,301,798

THREAD-THINKING MECHANISM FOR BUTTONHOLE SEWING MACHINES original Filedsept. 21, 1940 11 sheets-sheet 8 E. P. SPAINE Nov. l0, 1942.

THREAD-TRIMMING MECrIANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 21, 1940 l1 Sheets-Sheet 9 THREAD-TRIMMING MECHANISM FORBUTTONHOLE SEWING MACHINES Original Filed Sept. 2l, 1940 l1 SheetsUSheet10 11H1 f 56k 3mm t @amphi 'QJ/@2204x5529 Nov. l0, 1942. E. P. sPAlNETHREAD-TRIMMING MECHANISM FOR BUTTONHOLE SEWING MACHINES Original FiledSept. 2l, 1940 1l Sheets-Sheet l1 nl M EMM w m Mm 9&0. 3 y L. w, w 1 w.Zw. Fw/d m MVP c Patented Nov. l0, 1942 THREAD-TRIIWMIN G MECHANISM FORBUTTONHOLE SEWING MACHINES Edward P. Spaine,

Bridgeport, Conn., assignor to The Singer Manufacturing Company,Elizabeth, N. J., a corporation of New Jersey Original application September 21, 1940, Serial Divided and this application June 12, 1941,Serial N0. 397,682

(Cl. 11B- 252) 7 Claims.

This invention relates to buttonhole sewing machines of the adjustableautomatic type which cut and sew buttonholes of variable length withinthe range of the machine. Such a machine is disclosed in my copendingapplication, Serial No. 357,698, nled September 2l, 1940, of which thisapplication is a division.

The present invention has for an object to provide improvedneedle-thread trimming mechanism particularly adapted for an adjustableautomatic buttonhole sewing machine of the above described type, whichthread-trimming mechanism will cut and hold the needle-thread betweensewing periods, releasing the needle thread and at the begining of asewing operation and so controlling the needle-thread that the beginningend thereof will be drawn down flush withi the work.

Another object of the invention is to provide the thread-trimmer withimproved actuating mechanism to avoid clashing with the needle `or partsof the work-clamp.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations, and arrangements ofparts hereinafter set forth and illustrated in the accompanying-drawingsof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

In order to understand the construction and mode ot operation of thepresent invention it is necessary to describe the details ofconstruction and mode of operation of the automatic buttonhole sewingmachine in which it is embodied, as

set forth in my said copending application.

Oi the accompanying drawings, Fig. 1 is a right side elevation of abuttonhole sewing machine embodying the invention. Fig. 2 is a detailview of the thread-cutter actuating cam mounted on the one-revolutioncross rotary shaft located. in the machine-bed. Fig. 3 is a left sideelevation of the machine. Fig. 4 is a front end elevation -oi themachine with the lower plates of the workclamp in transverse section.Fig. 5 is a rear end elevation of the machine. Fig. 6 is a diagrammaticrepresentation of a square-bar buttonhole produced by th'e machine. Fig.7 is a bottom plan view of the machine. Fig. 8 is a horizontal sectionthrough the bracket-arm standard of the machine at the level of thebuttonhole cutter shaft and with the separable sections of the workclampremoved from the machine-bed. Fig. 9 is mechanism shown Fig, 8, at theperiod of the buttonhole producing cycle when the stop-motion latch istripped to stop the stitch-forming mechanism at the close of the returnside-stitching i operation on a -buttonho1e.

Fig. 10 shows the stop-motion latch holding the shiftable stop-motionlever in running position. Fig. 11 is a top plan view of thelongitudinal feed-cam and connections actuated thereby, including thelongitudinal feed uncoupling device an'd the auxiliary mechanism forreturning the work-clamp to initialposition after a buttonhole has beenstitched. Fig, l2 is a disassembled perspective view of the longitudinalfeed disabling connection or coupling.` Fig. 13 is a sectionsubstantially on the line l3l3, Fig. 1l. Fig. 14 is a sectionsubstantially on the line i4-l4, Fig. 11. Fig. 15 is an inside face viewof the auxiliary work-clamp return cam and follower connections whichare shown in top plan in Fig. il. Fig. 16 is an outer face view of thead- Justable pattern-wheel which is mounted at the left side of themachine-bed, externally of" the latter. Fig. 17 is a sectional viewsubstantially on the line l1-l|, Fig. 7. Iliig 18 is a sectional view ofthe pattern-wheel on the line |8-l8, Fig.-

16. Fig. 19 is a sectional view of the patternwheel on the line I9-|9,Fig. 16.

Fig. 20 is a sectional view of the pattern-wheel on the line 2li-20,Fig. 16. Fig. 21is a perspective view of the removable and replaceablebarstitch-controlling section of the lateral feed-cam in thepattern-wheel. Fig.,22 is a plan view of the back-feed and locking meansfor the longitudinal slide-frame of the work-clamp, taken just ,beforethe vback-feed is accomplished. Fig. 23 is a similar view taken justafter the back-feed is accomplished. Fig, 24 is a perspective view ofthe pattern-wheel, complete. Fig. 24l is a fragmentary elevational viewof the pattern-wheel showing the bar-stitch start-and-stop controlsegments for the stitch-forming mechanism. Fig. 25 is a disassembledperspective view of the pattern-wheel. Fig. 26 is a development of thelateral feed-camsgroove in the pattern-wheel. Fig.

27 is a. central longitudinal section of the develop..

ment shown in Flg.26. Fig. 28 is an enlarged view of theneedle-thread-cutting mechanism shown in Fig. 4. Fig, V29 is atransverse sectional view of the thread-cutting and thread-nippingblades of the thread-cutting mechanism.

Fig. 30 is an elevation of the thread-cutting mechanism, the reverse ofthat shown in full lines in Fig. l28. Fig. 31 is a top face view of aplan view oi' the stop-motion latch-tripping 55 the thread-wiwi'blade'hOldeI' Complete F18 32 is a similar view of the thread-cutterbladeholder, with the cover-plate removed. Fig. 33 is a view of thecover-plate for the parts shown in Fig. 31. Fig. 34 is a section on theline .3d-34, Fig. 31. Fig. 35 is a sectional view on the line -35-35,Fig. 34. Fig. 36 is a perspective view of the thread-cutter supportingbracketshown in Fig. 30, and Fig. 37 is a disassembled perspective viewof the thread-cutter swing-controlling cam and associated parts, shownin Fig. 30.

The machine is constructed with a frame including the hollow box-likebed I from one end of which rises the standard 2 of the overhangingbracket-arm 3 terminating in the head 4.

The stitch forming mechanism is constructed substantially in accordancewith the disclosure of U. S. Patent No.` 1,372,473, dated March 22,1921, and comprises the usual upper endwise reciprocatory and laterallyvibratory needle 5 and under thread-looping devices including thethreaded looper 6 and loop-retainer 1, which upper and understitch-forming devices are mounted to turn about a vertical axis, as inplacing the stitches radially about the eyelet-end of a buttonhole. Thewell known mechanism for turning the stitch-forming devices about avertical axis is constructed substantially in accordance with thedisclosure of U. S. Patent No. 1,162,207, dated November 30, 1915; No.1,534,017, dated April 2l, 1925 and said reissued Patent No. 15,324. Themechanism includes the intercannected upper and lower sector gears 8 and9 and the stitch-rotating cam-groove Il), Fig. 7, which is cut in theunder face of the main feedwheel II mounted as usual in the bed I.

The stitch-forming devices are driven as usual from the main sewingshaft I2 which `receives power from the continuously running belt pulleyI3 through a known form of clutch I4 controlled by the usual stop-motionlever l5 which is tiltable with its supporting rock-shaft I6 from fullline or stop sewing position, Fig. 3, to dotted line 'or runningposition, to start the sewing operation. The stop-motion lever I5 isbiased to stop sewing position by the spring I1 and, when permitted,will automatically resume its stop sewing position.

When the stitch-forming mechanism is being driven, the main feed-wheelII receives a slow step-by-step motion through the gears I3, Fig. 7,from the pin-and-star wheel device i9 which is driven by the main sewingshaft l2 in the usual manner through the bevel gears 20 and verticalshaft 2I from which the upper or needleoperating shaft 22 is driven. Themain feedwheel II is permanently connected by the large bevel gears 23to the cross rotary shaft 2li in the bed I which cross rotary shaftcarries the adjustable pattern-wheel Zito be more particularlydescribed.

The work-clamp is o f the travelling type and is constructedsubstantially in accordance with said reissued Patent No. 15,324. Itcomprises the lower clamp-plates 26 and the upper clampfeet 21 which aredepressed into clamping engagernent with the work by the connectedrockshaft sections28, 29, Fig. 4, the former of which is connected to anarm 30, Fig. 1,- adapted to be depressed by the usual clamp-closinglever 3i actuated at the beginning of a buttonhole-making cycle by acam-groove 32, Fig. 5, in a continuously running belt-pulley 33 loose onthe buttonhole cutter shaft 34. A slide-pin 35, carried bythe rearwardlyextending arm 36 of the clamp-closing lever 3l is permitted to enter thefeed-cam groove 39 in the main feed-wheel II operating on the followerlever 40 fulcrumed at 4I on the bed I and connected at its free endthrough a disconnectible coupling device c, Fig. 12, to the longitudinalslide-frame 38.

The disconnectible coupling device c, whereby the longitudinal feed ofthe machine may be disabled, comprises the block 42, Fig. 12, having atone end an ear 43 by which it is pivotally connected at 44 to the freeend of the lever 40. Drilled in and longitudinally of the block 42 is ahole 45' which slidably receives the pin 45 having at one end a head 46which is pivoted at 41 to the block 48 screwed to the under side of amember of the longitudinal slide-frame 38 of the work-clamp.V Journaledon the block 42 is a spring-biased rock-shaft 49 having rigidly mountedthereon a safety latch-arm 50 received in a safety recess 5I in the sideof the pin 45. The rock-shaft 49 also rigidly carries a latcharm 52which engages behind the lug 53 on the side of the head 46 of the pin 45when the safety latch 50 enters the notch 5I. At this time the head 46of the pin 45 is in engagement with the proximate end of the block 42and is locked there by the latch 52. The safety notch 5I and arm 56prevent interference between the latch 5' and lug 53 until the lug 53reaches a position where the latch 52 is free to drop in behind it, Fig.11. Fast to therock-shaft 49 is the upstanding operating arm 54 whichextends across the outer edge of the lever arm 55, Fig. 3, fast on thevertical rock-shaft 56 journaled in brackets 51 at the left hand side ofthe bed I. The rock-shaft 56 also has fast thereto the rearwardlyextending stopmotion-latch-tripping arm 58 and the forwardly extendingYarm 5,9 which is acted upon by the cam-rise 60 on the pattern-wheel 25.

The stop-motion lever I5 is, at times, latched in running position bythe spring-biased latch lever 6I which is fast on the verticalrock-shaft 52 journaled at the rear end of the bed I. The lever 6I has anotch aording a locking shoulder 53 engaged by the angle-piece 64 on thearm 65 depending from and fast on the rock-shaft i6 which carries thestop-motion lever I5. The rock-shaft 62 also carries the lever-arm 66having a roller 61 in position to be engaged by the stop-motionlatch-tripping arm 58, as shown in Figs. 9 and 10.

Means are provided to lock the longitudinal slide-frame of thework-clamp against movement on the bed I whenever the longitudinalfeedcoupling c is disconnected. To accomplish this, there is securd to thelongitudinal slideframe 38, Fig. 9, a rearwardly extending bar 68, I

- hole.

ly, thus imparting a small reverse movement or second or return sidestitching operation of the buttonhole, before the barring operation.

The lateral feed motions of the work-clamp which are compounded with thelongitudinal feed-motions of the work-clamp to sew around a buttonholeare, in the present machine derived from the lateral feed-cam groove 13in the pattern-wheel 25. The cam-groove 13 is entered by the lower endof the slide-bolt 14 which is carried by the lateral feed-lever 15fulcrumed at 18 on the bed I and carrying at its forward end a block 11which is received in the longitudinal slideway 18 in the block 19screwed to the crossslide plate 31. The slide-bolt 14 is carried in thecylindrical boss 80 at the rear end of the lever 15 and has afinger-piece or pin 8l projecting laterally from it through an invertedL-shaped slot 82, Fig. 16, in the boss 80. When this pin 8| is turnedinto the vertical leg of the inverted L-shaped slot, it is depressed bythe leaf-spring 83 to the lower end of such slot, In this position theslide-bolt 14 is free to ride the bottom of the lateral feedcam groove13 and to follow and be controlled by said cam groove even in theregions 84 where the cheeks of said groove are cut away to a certainradial extent or level. When the slide-bolt is raised to its higherlevel and the finger-piece 8| thereof turned into the horizontal portionof the inverted L-shaped slot 82, Fig. 16, the slide-bolt still runs inthe cam groove 13 and is controlled thereby in all regions thereofexcept the region 84 where the cheeks or side walls of the cam groove 13are cut away. It is in this region that the cam groove 13 controls thelateral feed of the work-clamp in sewing around the eyelet end of thebuttonhole. When it is desired to produce a straight buttonhole, thatis, a buttonhole having no eyelet end, the slide-bolt is raised to itshigher position, Fig. 16, so that it is not under the control of thecam-groove 13 when encountered by the cut away side-portions 84 at theeye-forming portion thereof. At this period of the cycle the travellingkey 85 on the bracket 86 fastened to the longitudinal slide frame 38enters a diametrical slot 81 in the upper end of the slide bolt 14 andlocks the work-clamps against lateral displacement when out of controlof the lateral feed-cam groove 13. When in its lower position lthe slidebolt 14 is not encountered by the locking key 85. Thus, by setting theslide bolt 14 in either of two positions, the machine may be made toproduce either an eyelet-end or a noneyelet-end buttonhole, at the willof the operator.

The longitudinal feed-cam groove 38 is designed to impart to thework-clamp a certain fixed overall longitudinal motion. At the start ofa buttonhole-producing cycle the work-clamp occupies a position at oneextreme end of its range of longitudinal traveling movement, known asbuttonhole-cutting position.` When the machine is started, the connectedfeed and pattem-vcheels H, 25, are at rst driven by a rapid-feed drivingmechanism to carry the work-clamp quickly from starting position to thepoint of its longitudinal motion where the stitching is to begin. Whenthis point is reached the stitch-forming mechanism is started and therapid-feed drive is thrown out. The stitching then progresses down thefirst sidev of the buttonhole, around the eyelet-end and back along thereturn side of the buttonhole to a point adjacent the rst stitch, atwhich point the .stitch-forming mechanism is stopped. In machines of theprior` art adapted to sew unbarred buttonholes of variable length it iscustomary at this point to throw in the rapid feed driving mechanism toeffect a quick return of the workclamp to its initial position(buttonhole cutting position). In other machines of the prior artadapted to sew taper-barred buttonholes of variable length such, forexample, as the machine of U. S. Patent No..2,190,614; February 13,1940, the lateral feed-cam includes two barring camsections which areperipherally adjustable to vary the timing of their operation in thelongitudinal travel of the work-clamp,

The present machine works on a different principle. Here, the lateralfeed-cam has only one barring cam-section 88, Figs. 18, 21, 26 and l2'?.This barring cam-section is fixed in its timon the pattern-wheel as toencounter the follower slide-bolt 14 as soon as practicable aftercompletion of the return side stitching operation of the longestbuttonhole within the range of the machine. For shorter barredbuttonholes, instead of providing for a change of timing of the barringcam-section 83 by adjusting it peripherally of the pattern-wheel, it is,in the present machine, retained in a fixed position on thepattern-wheel and, when the return side stitches of the buttonhole arecompleted, the sewingmechanism is stopped, the work-clamp isdisconnected from the longitudinal feed-cam and locked againstlongitudinal shift. The rapid-feed is thrown into drive the feed-camsystem idly around to bar-stitch sewing position, whereupon the sewingmechanism is again started and stopped to sew the bar. After this, therapid feed-drive is again thrown in to operate an auxiliary mechanismtoreturn the work-clamp to its initial or buttonhole cutting positionwhere it is reconnected to the longitudinal feed-cam in readiness forthe next buttonhole-producingcycle.

In the work of the present machine, the bar is what is known as asquare-bar. That is, it is sewn square across the end of the buttonhole.Tp accomplish this, itis preferable that the sewing mechanism be turnedabout its vertical axis, say between the time of completion of the lastside stitch and the rst bar stitch. 'I'here is thus an intimate timedrelationship between the barring cam-section 88 on the pattern-wheel andthe eccentric stitch-rotating portion I0' of the stitch-rotatingcam-groove lil in the main feed-wheel I l. This relationship is notdisturbed by any adjustment of the present machine. The timing is maderight for the longest buttonhole within the range of the machine and,for shorter buttonholes, the cam-system is rapidly and idly turnedvariable angular distances, depending upon the length of the buttonhole,from the variable 'position wher'e the sewing mechanism is stopped atthe completion of the return sidestitching operation, to an invariablebarring` position.

The pattern-wheel with which the present machine is equipped comprises amain supporting disk 89 having avlarge cylindrical extension 90constituting a bearing or arbor for a pair of internally toothed rings9|, 92. These rings are held on the arbor 90 by the face-plate 93.Journaled in the coaxial holes in the disk 99 and faceplate 93 is` theshaft l94 to which is fixed the 94 is fitted with the knurled head 90 bywhich it may be turned to adjust the rings 9|, 92 simultaneously and toequal extents in opposite directions upon and relative to the disk 89.The rings may be clamped in adjusted position by the clamp-nut 99 andpressure head |00, Fig. 19, carried by the small plate IOI under the nut99 which is threaded upon the bolt |02 passing through the disk 09.

The inner ring 92 carries the start-sewing cam rise segment |03 theouter edge of which engages the follower nose |04 of the lever |05,connected by the link |06 to the lever arm 55 of the stop-motion deviceto shift the stop-motion lever I5 to its dotted line or running positionFig. 3; the cam-segment |03 having a total height suiilcient to shiftthe lever-arm 55 far enough for the shoulder 53 of the latch-lever 5I toengage the angle piece 94 and latch the stopnotion lever I5 in runningposition. As shown, the cam-segment |03 has a rather abrupt nose whichinitially engages the follower |04 and has a rise suilicient to shiftthe levers 55 and I5 far enough to start the sewing mechanism but notfar enough to allow the latch 5| to drop into retaining positionrelative to the lever 95. The abrupt nose of the cam-segment |03 isfollowed by a more gradual rise terminating ai; the crest |03' which ishigh enough to permit engagement of the shoulder 53 of latch 6I with theanglepiece 54 on lever 65. This provides an easy metion of the parts tosewing position and relieves the parts 'of undue strain. The outer ring9i, Fig. 25, carries the stop-sewing cam 80 which trips the latch 9| atthe end ofthe return side stitching operation. The cam has an arcuatetail portion |01 which holds the follower-lever 59 and longitudinalslide-frame locking tooth 1| in the locking position, Fig. 9, untilafter the bar Ais] sewn. Each oi the elements |03 and 60 is peripherallyadjustable upon its respective ring carrier 92 and 9|, as shown in Fig.25.

There is screwed to the face-plate 99 a segmental plate |00 which isthick enough to meet the operative edge of the tail-piece |07 of thelongitudinal slide-frame locking carri and hold the lock on, after thetail-piece |01 rides beyond the follower-lever 59. The segmental platehas an end shoulder |09 which finally releases the follower-lever 59 tounlock the longitudinall slideframe and release the latch-lever 54 ofthe coupling device c, between the longitudinal slideframe andthelongitudinal feed-cam lever 40.

This occurs in the inal rapid-feed of the camsystem after the bar-sewingoperation is conipleted.

The present machine may be adjusted to sew buttonholes with or withoutan eye and to sew around or to suspend sewing at the eye end. To

sew a buttonhole without an' eye and with sewing suspended, means areprovided to stop and start the sewing operation at the eye end of thebuttonhole. To this end the locking bar 58 extending rearwardly from thelongitudinal slide-frame '3s is steed at its free end with a cross slidepm I0 'which may be manually shifted from inoperative position shown infull lines in Figs. 5, 8 and 9 to dotted line position, Fig. 8, whereits enlarged head-end H0 is effective to engage the reduced upper end61" of the roll 51 and trip the latch-lever 6| to release thestop-motion lever I5 and stop the stitch-forming mechanism, when thelongitudinal slide-frame nears the end of its initial travellingmovement. The cross slide pin ||0 is mounted in a block H0, Figs. 3 and8, which is mounted for adjustment on and lengthwise of the longitudinalslide-frame extension bar 6l, by the usual screw ||0b and slot ||0expedient. Thus, the point at the end of the buttonhole where the ilrstside stitching operation may be stopped, is variable by adjustment ofthe slide-pin ||0 lengthwise of its carrier bar 50.

To start the sewing mechanism for the sewing of the return side of thebuttonhole there is adjustably mounted on theI pattern-wheel disk 09 astart-sewing cam-segment ||I which is in the same plane as thecam-segment |03 previously described and, like the latter, has an abruptnose followed by a gradual rise sufilcient to shift the stop-motionlever to a position where it will be retained in runningposition by thelatchlever 6|, after the segment rides beyond the follower-nose |04'.

There is screwed to the thick segmental plate |08 a thinner segmentalplate ||2 which has a cam-incline ltimed to engage and operate .thelower horizontal leg ||4 of the needle-thread tension-release lever l|I5 ata time in the cycle immediately after completion of the bar sewingoperation and 'substantially simultaneous with the unlocking of thelongitudinal slide-frame. The needle-thread tension-release mechanismbetween'the levergI I5 and the tension device Iii is of usualconstruction and is disclosed in U. S. Patent No. 2,165,016, July 4,1939. When the machine is at rest, Fig. 3, the needle-thread tensiondevice ||Q0 "is held released. It is restored during the initial rapidfeed of the work-clamp from buttonhole cutting position to the positionwhere sewing begins; when the machine is set to produce the longestbuttonhole Iwithin its range.

To start and stop the stitch-forming mechanism for the sewing of the barthere is secured directly to the pattern-wheel body-disk the segmentalplates II'I, IIB, the former presenting the start-bar-sewing cam-riseII9 and the latter the stop-bar-sewingf drop-oi! shoulder |20 whichplates ride under and are engaged bythe follower nose |04 oi thestop-motion control lever |05. The outer radially coincident edges ofthe segmental plates |I1 are not high enough-to displacethe stop-motionlever 65 far enough for engagement of the latch II with the angle-plateEl, consequently the follower-nose |04 rides the coincident circularedges of the segmental plates ||`I, iI throughout the bar-sewing periodand the sewing stops when the nose |04 drops o1! of' the shoulder |20.The plates'I II, III are secured to the body disk 09 by the screw |2Iwhich passes through arcuate slots in the plates Ill, ||3 permittingindependent timing adjustments thereof. The purpose for theseadjustments is to compensate for either an increase or decrease of thewidth of bight of the sewing, or width of buttonhole cutting spacebetween the side stitches of the buttonhole, which changes would callfor an increase or decrease in the length of the stitched bar. Also,theseadjustments permit the bar to be shifted to the right or left ofthe buttonhole.

'stitched and barred, the longitudinal slidevcutting position. To thisend there is provided an' auxiliary clamp-shifting mechanism, asfollows:

Cut in the inner face oi' the bevel gear 23 on the cross rotary shaft 24of the cam system of the machine is the cam-slot |22, Fig. 15, entered.by the follower roll |23 on the vertical lever-|24 fulcrumed at |25 onthe frame-bracket |24. 'I'he lever |24 is connected by the link |21 tothe horizontal lever |25, Fig. 11, fulcrumed on the bearing stud |25which supports the main feed-wheel Il and carrying at its' free end aroller stud |30-in position to engage and operatethe floatingintermediate lever |3| fulcrumed at |32 on the bed i. The lever |3|floats between the roller stud |30 and the head 45 of the coupling rod45 which pivotally carries the block 41 screwed to the 1ongitudinalslide-frame 35. The function of the floating lever |3| is to transmitthe rather sharply curved or arcuate motion of the roller-stud |30 onthe lever |28 to the rectilinearly movable head 45 of the coupling rod45 in pushing the longitudinal slide-frame back to initial position. Theportion of the cam-slot |22 from a to b, Fig.A 15, acts to restore thelongitudinal slide-frame to initial position, while the portion from dto e is shaped to withdraw the lever |25 from the oating lever 3| fastenough to avoid blockingthe After the buttonhole has been completely.

advance of the longitudinal slide-frame under the influence ofthelongitudinal feed-cam 39 early in a buttonhole-producing'cycle. `Whenthe lever 59 is released by the patternwheel shoulder |59 to unlock thelongitudinal slide-frame and release the latch-lever 54 'from its dottedline position, Fig. 14, the rock-shaft 49 and safety latch-arm 59immediately move under the influence of their biasing spring until thenose of the lever 5l engages the cylindrical wall of the coupling rod 45on lwhich it rides until the rod and longitudinal slide-frame 35 arerestored to initial position, whereupon the nose 50' drops intothe'safety-noich 5|, as shown in Fig. 14, and the latch-arm 52 engagesbehind the latter to the block 42. 'I'his re-connects the longitudinalslide-frame 35 to the longitudinal feedcam 39. When the machine is atrest, Fig. i1, the lever |29 and follower-roll |30, with the floatingintermediate lever |3| are at one extreme posltion and serve to lock thelongitudinal slideframe against movement from initial position until themachine is started, whereupon the follower-roll |30 is withdrawn asabove explained.

'I'he rapid feed mechanism is called upon to operate at least threetimes in the buttonholeproducing cycle of the presentmachine; first, to

'lug 53 on the slide-pin head 45 and locks the rapidly shift thework-clamp from buttonhole- ..79

over to y release the l toothed lever |54 cutting position to a is tobegin; second, toidly turn the feed-cam system to barring position atthe close of the return side stitching operation; and third, to restorethe work-clamp to buttonhole-cutting posi-I tion after the bar is sewn.It may be called upon to operate to rapid feed at the eye end of anoneyed buttonhole, 1n case the machine is set to stop the sewing nearthe end of the first sidestitching operation by setting the slide-pin `Ii0 in its dotted line position, Fig. 8. A

'I'he rapid-feed drive of the connected feedcam and pattern-wheel 25, isaccomplished by the constantly running rapid-feed drive-shaft operatinglevers,.the clutch is engaged and the shaft -24 is coupled to itsdrive-shaft |33 or. in other words, the rapid-feed is thrown in. Thisrapid-feed mechanism is, so far, constructed substantially in accordancewith the disclosure of said U. S. Reissue Patent 15,324. Theclutch-operator is constituted by a crossslide rod |4I carrying an arm|42 having at its free end a fork |43 which engages the grooved hub ofthe cone |40. The cross-slide rod |4| is biased by the coil-spring |44in a direction to throw out the rapid-feed. 'I'he rod I4| is shovedendwise against the pressure of the spring |44, to throw in therapid-feed. by the continuouslyreciprocating push-bar 45 which ispivoted at |45, Fig. 5, to the arm |41 of a bell-crank |45 actuated bythe crank |49 the rapid-feed drive-shaft |33. The push-bar |45 is heldby the latch |50 in .a depressed position, Figs. 1 and 17, where it mayreciprocate idly. When the latch |50 is swung push-bar |45, the latteris drawn upwardly by its spring |5|, effecting engagement oi thestud-pin |52 on the cross-slide shaft i4| by the shoulder |53 on thepush-bar |45 whichthereupon shoves the cross-slideshaft `|4| to itsextreme rapid-feed throw-in position in which it is retained byengagement of the shoulder |54 on the latch-lever |55 by the lower edgeof the plate |55 on the hub of the forked arm |42.

The latch |50 is engaged by a lever-arm |51 on Ithe rock-shaft |55 whichis journaled in thebed i and has rigidly connected to it two arms |59,|50 by means of which it may be operated to throw in the rapid-feed. Thefirst mentioned arm |59 carries a spring-pressed tripping tooth ISIwhich is engaged and depressed bythe pin |52 on the downwardly extendingarm |53 of the three-armed clamp-closing lever 3|, 35, |53,

which at the beginning of. a buttonhole-prov ducing cycle receives animpulse from a clampclosing cam-groove in the inner face of thecontinuously running belt-pulley33 loose on the buttonhole-cutter shaft34,l previously referred to. The seoondmentioned arm |50 of therock-shaft |58 is actuated to throw in the rapid-feed by the whichengages the arm |50 whenever-` the stop-motion lever l5 acts to stop thesewing operation. The actuating mechanism for the toothed lever is thesame as that disclosed position where the sewing lateral extension Thethrow-out of the rapid feed is accomplished by tripping the latch-lever|55 to release the spring-biased clutch-operator slide-rod |4|. Thelatch-lever |55, Figs. 5 and 11, has an extension 6 2,301,798 -m' u.' s.Patent No. 1,504,306, of august 12, 1924.

|65 which enters the forked end |69 of a lever |61 fulcrumed at |69 onthe inner wall of the. bed I. 'I'he lever |61 has a free end portion |69which is in position to be engaged by the -rapidfeed throw-out tooth |10fixed on the inner face o1' the pattern-wheel 29. The tooth |10 is thetooth which throws out the final rapid-feed ac- .,tign after thework-clamp has been restored to 'f tuttocuore-cutting position at theclose or a butltombale-producing cycle. `All of the rapid-feed'- actionsin the present machine which precede this iinal rapid-feed action areterminated by the shift of the stop-motion control link |09 through theusual mechanism disclosed in U. S. Patent No.

2,190,614, February 13, 1940. s'uen mechanism includes the upstandinglink-actuated lever |'1|, Fig. 1'7, fulcrumed on the screw |69 andhaving a thrust-bar |19 which is fulcrumed at |14 be- Vtween the spacedears rigid with the lever |61. 'Further details of this known mechanismare fully disclosed in said U. S. Patent No. 2,190,- 614 and need not bemore particularly described herein. It will sufce to explain that everytime thelink |06 is shifted endwise to start the sewing mechanism, theimmediately preceding rapid-feed action is automatically thrown-out byaction of the lever |1| on the lever |61 through the thrustbar |13. Thisautomatically takes care of (1) the `discontinuance of the initial rapidfeed of the work-clamp from starting position to the position where thesewing is to'begin; (2) the |12 which bears upon the.

which is rigidly mounted a uuu exea blade in. having a shear cuttingedge |99. Fulcrumed on the pin |90 is the movable blade 9| having aVshear cuttingedge |92 complemental to the fixed shear cutting edge |89.The body-member |91 has a slideway |99 cut longitudinally thereof and inthis slideway is located the slide-bar |94 having in one 'edge asemi-circular recess |99 for' the circular end |96 of the movable blade|9|. A

biasing spring |91 connects a pin |99 on the slidebar |94 to a xed pin|99 on the body-plate |91.

This spring urges the movable cutter to close to full line position,Figs. 29 and 31. A cover-plate 200, having a hook 20| at its lower end,is screwed to the body-plate |91 to hold the slide-bar and movablecutter-blade in their respective ways in the body plate |81. From theforegoing it willv be apparent that a push at the end of 'the bar |94remote from the shear cutters will open the latter and when such a pushis relieved the cutters will close and'sever the thread, at the sametime y nipping the needle end of the thread between the movable blade 9|and the cover-plate 299.

The body-plate |01 and parts carried thereby is screwed to the -head 202of a tubular shaft 299 which is ,'iournaledv in a bearing support at onediscontinuance of the-rapid feed at the eye-end of the buttonhole whenthe machine is set to sewv a non-eyed buttonhole and the sewing isstopped and started at such end to avoid overcrowding of the stitches;and (3) the discontinuance of the rapid-feed action between the returnside stitching operation and the bar stitching operation. The finalrapid-feed action is, as before .explained, terminated by action of thetooth |10 on the lever |61.

The lmachine has a conventional under thread tension-device |16, Fig. 4,and spring-biased tension-release lever |11 fulcrumed at |19'on thebed-frame and carrying two spaced pins |19 'ibetween which extends thearm |90 of a rock-shaft I9| extending with and lengthwise oi' thebed andthrough the rear end wall oi' the latter where it carries the arm |92that is acted upon by the inclined face |93 of a block |04 carried atIthe lower end of the stop-motionoperating lever 65. The mechanismfunctions to release the under thread tension when the stop-motiondevicefunctions to stop the stitch-forming mechanism. The

. mechanism is fully disclosed in U'. S. Patent No.

2,210,638; granted August 5, 1940.

The machine has the conventional buttonholecuttingmechanism includingthe enacting upper and lower cutter levers |95, |96, Fig. l, which aredriven in the usual manner by the one-rotation buttonhole-cutter shaft34. While the present. machine is designed to cut the buttonhole aftersewing, itis entirelyimmaterial to the inven- -tion whether thebuttonhole is out before or after sewing. l

The machine is provided with the following means to cut and hold theneev:llethread. The thread-cutting and -nipping implement nconiprises athick plate-like body-member |91 on ment to the thread-cutter implementon the axis of its tubular fulcrum shaft 209 .relative to itscarrier-lever 204, when such carrier-lever is operated to advance thethread-cutter implement from retracted position (dotted lines Fig. 29)to threadcutting position/ (full lines Fig. 28).

Journaled in the tubular fulcrum shaft 299 is a rock-shaft 2|9 having atone end a' tappet arm'2l4 the toe end 2|5 of which is so positioned 'asto engage and push upon the end of the slide- Y bar |94 to open thethread-cutter blade |9|. The

rock-shaft zn has .nxedwits opposite emi a' crank-arm 2|6 carrying atits free end the pivoted and spring-biased toe-piece 2|1 which, in thecutter-advancing movement of the carrier-lever 204 engages the cam-piece2|9 of the arm 2|9 fixed to the bracket 201. This engagement of thetoe-piece 2|1 with the, cam-piece 219 rocks the shaft 2|3 in thevtubular shaft 209 and causes the tappet toe'2l6 to push in the,slide-bar |94 and open the cutter-blade |9|. As soon as the toevpiece2|1 passes beyond .the cam-piece 2|9'the slide-bar |94 is released anddrawn by its spring |91 to close the blades |9|, |99, 209 upon theneedle-thread, as shown in Fig. 28. In the return movement of thecarrier-lever 294, the toppiece 2|1 wipes idly past the cam-piece 2|9,being free to swing on its pivot-screw 2|9in this direction.'I'hestop-screw 220, which is engaged by the tail 22| ofthe toe-piece2|1, prevents swinging of the toe-piece 2|1 inthe reverse direction whenthe thread-cutter is advanced to full line position, Fig. 28.- V

When the thread-cutter is retracted after -cutting and nipping theend ofneedlethread leading to the needle 5, the heel 222 of the tappetarm 2Mis brought intoengagement with the stationary abutment' 229 verticallyadiustably mounted on the bracket-arm head 4 of the machine freme. Theinitial engagement ofthe heel l lower the release of the portion 239,

ary thread-guides 245.

'instrumentalitiea The usual gimp or cord G to engage and operate thelever ascuas 222 with the abutment 222 is a mere contact, not sufficientto cause the tappet-arm 2|4 to open the thread-nipper blade ISI. Aslight further retraction of the carrier-lever 204, before the initialstitch oi the next buttonhoie is made,

I by the unam to the crooked lever 22s which 1s screwed to a lowerlever-arm 235 fulcrumed at 23|' within thev standard 2 and having at itsend a roller 2li tracking the cam 232 onthe cross rotary shaft 24. Thespring 223, Fig. l, applied'to the lever 22l'retalns the follower-roll2li against the cam 232. Thevcam 232 has a let oil' notch 234 whichreleases thelever 229 and v'allows' the thread-cutter to'advance and cutand seize the needle-thread during the final rapidfeed movement of thecross rotary shaft 24. The cam 222 also has a slight rise at 235 toeifect before the needle starts down on its nrst stitch. This releaserise terminates at lthe point 235, Fig. 2.

To pull suiilcient slack needle-thread from the supply for the beginningof the sewing operation,

, there is secured to the clamp-closing lever il,

Fig. l', a pull-off rod 231 which rises through the guide 235 and has atits upper end a horizontal Fig. 3, working between two station- At thetime the clampclosing lever 3i operates, the needle-thread tension isheld open by the lever H5 and tail of the tension-release segment H2 onthe patternwheel 25. 'Ihe pull-ol! is adjusted to measure enoughneedle-thread from the supply so that the beginning end of needle-threadwill be drawn down flush with the work by the stitch-forming is suppliedto the needle-throat member 2li through a gimp pulloil' and slack-givingdevice including the gimpiension device 242 which is carried by thelever 242, Fig. 1. actuated by the cross-rotary shaft 24, substantiallyin accordance with the disclosure of U. S. Patent No. 2,210,638, grantedAugust 6, 1940.

Operation The operation is briefly as follows: At the stnrt of theoperation the tripping of the clamp-closing mechanism causes theactuation of the threearmed clamp-closing lever li, 55, ill which closesthe work-clamp and actuates the needle-thread pull-01225. The threadtrimmer is in retracted position and is closed. The recovery motion ofthe clamp-closing'lever causes the stud-pin |82 |59 to trip therapid-,feed into action to shift the work-clamp from initial position tothe position where sewing is to begin. In that shift of the work-clampthe thread-trimmer is further retracted to cause the stationary abutment223 to release the needlethread end. The pattern-wheel cam-rise Il!starts the sewing mechanism; the stop-motion lever being latched inrunning position. The

vsewing startsat the point s, Fig. 6, and continues tozand around theeyelet-end t to the point u which ls a little short of the startingpoint s measured lengthwise of the buttonhoie. When -tm end point u isreached the stitch-forming mechanism is stopped and the longitudinalslidei stop-motion causes the pawl A the bar-sewing beginning end ofneedle-thread initial position, the closed thread-cutter is rethreadend.

thread. 'I'he tension vi'ra'me of the work-clamp is uncoupled from thelongitudinal feedcam.and given va slight reverse feed movement by theinclined face 12 of vthe locking pin 1i which locks the longitudinalslideframe in barring position. The action of the i64, Fig. 1, to tripthe rapid feed into operation to feed the cam system idly around to aconstant barring position Just previous to which the stitch-formingmechanism is preferably turned around its vertical axis-to bar-stitchingposition.

I'he cam rise H8 on the pattern-'wheel starts operation which proceedsfrom the point v, Fig. 6. square across the end of the buttonhoie to thepoint w. It will be noted that the bar overlaps the end stitches at bothsides cut after the bar is completed' and before the work-clamp isshifted out of barring position.

When the machine ls at rest, the thread-cutter is in its retractedposition closed upon the end of needle-thread running to the needle.When the machine is started, the pull-off is operated by theclamp-closing lever to pull a constant amount of thread from the supplyso that the initial thread end will be drawn down flush with the work inthe formation of the rst stitch. During the initial rapid feed movementof the cross-rotary shaft 24, before the sewing starts, thethread-cutter is further retracted 'by the rise 235 on cam 222sumciently to release the needle- This occurs before the work-clamp ismoved away from initial position. The machine now sews and bars thebuttonhoie. Early in the iinal rapid feed, after barring, thethreadcutter is advanced and closed upon the needleis released by thecam inoline III on pattern-Wheel segmental plate i i2. During reverserotation of stitch-forming mechanism and return movement of work-clampto tracted to initial position and it pullsV a constant length of threaddownwardly through eye of needle for any length buttonhoie the machinemay be set to produce, to begin the next sewing operation and secureuniformity in the iinal hidden disposition of the beginning end ofneedlethread flush with the work.

The present thread-trimmer is mounted to` operate in a fixed path withrespect to the sewing needle while the work-clamp is locked in barringposition regardless of the length of the buttonhole within the range ofthe machine.

The compound motion of the thread-trimmer, shown by the upwardly convexcurved dot-anddash line in Fig. 28, carries the trimmer over the top ofthe clamp-foot 21 and thence downwardly to clear the needle-point byasufficient margin.

Having thus set forth the nature of the invention, what I claim hereinis:

l.' A buttonhoie sewing machine having stitchforming mechanism includingan upper endwise reciprocatory needle, a work-holder, feeding mechanismto relatively move the stitch-forming mechanism and work-holder into andout of sewing relation* and to sew about a buttonhoie, a stop-motiondevice for the stitch-forming mechanism adjustable to vary the times o!starting and stopping of the stitch-forming mechanism.

whereby buttonholes of various lengths may be sewn, a thread-trimmerAmounted at the needle side of the work independently of the workholder,and means to actuate said thread-trimmer at the close of a sewing periodand before the 'stitch-forming mechanism and work-holder arel relativelyshifted out of sewing relation.

2. In a buttonhole sewing machine, the combination with stitch-formingmechanism including an upper thread-carrying needle and complementalunder thread mechanism, work-holding means, feeding mechanism includingfeed-- cams and connections for relatively moving the stitch-formingmechanism and work-holding means to sew about a buttonhole, a rapid feeddrive including a cro rotary shaft journaled in the machine bed andconnected to said feed-cams for driving the latter between sewingperiods, a

needle-thread trimmer mounted above the workholding means, anda cam onsaid cross rotary shaft and connections for operating said needlethreadtrimmer.

3. In a sewing machine, a

crumed on said bracket-arm, a thread-cutter comprising acomplete-,scissors device mounted for pivotal movement on and relativeto said lever. a cam for controlling said pivotal movement, and means toactuate said lever to advance frame including a bed and an overhangingbracket-arm, a lever fulsaid thread-cutter from a retracted position toa thread-severing position.

4. In a sewing machine, a frame including-a bed and an overhangingbracket-arm, a lever fulcrumed on said bracket-arm,I a thread-,cuttercomprising a complete scissors device mounted for pivotal movement onand relative to said lever, a cam for controlling said pivotal move- Ament, and means to actuate said lever to advance said thread-cutter froma retracted position to a thread-severing position, and means to openand close said scissors device in the advancing movement of the latter.

5. A buttonhole sewing machine having stitchi forming mechanismincluding a"reciprocatory eye-'pointed needle and complemental underthread mechanism, a stop-motion device for the 1 stitch-formingmechanism, a tension device for the needle-thread, an automatic tensionreleaser,A

a needle thread cutter and nipper mountedv at the needle side of thework for bodily movement.

from retracted position to thread-cutting and -nippingl position andreturn, anl automatic needle-thread pull-off device operative on theneedle-thread before it is released by said nipper,`

and means to effect the release of the needlethread by said nipperbefore'the needle descends i on the first stroke of a sewing period.

6. In a sewing machine, a thread-carrying needle, a needle thread-cutterand -nipper, a carl rier therefor, means to actuate said carrier toadvance said thread-cutter and -nipper from a retracted position toneedlethread-cutting and nipping position and return, means to impart afurther retractive movement to saidthread-v cutter and -nipper, and anabutment engaged by said thread-cutter and -nipper in'its furtherretractive movement andoperative to open said nipper and release theneedle-thread end.

7. A buttonhole sewing machine having stitchforming mechanism includingan upper endwise reciprocatory needle, a work-holder, feeding mechanismto relatively move the stitch-forming mechanism and work-holder 'intoand out of sewing relation and to sew about a buttonhole, a stop-motiondevice 'for the stitch-forming mechanism adjustable to vary the times ofstarting and stopping of the stitch-forming mechamsm, wherebybuttonholes ofV various lengths may be sewn. a combined thread-trimmerand thread-end-holder mounted at the needle side of the workindependentlyof the work-holder, means to advance said thread-trimmer'and thread-end-holder and to close the same on the 4thread leading fromthe needle-eye to the last for buttonholes of any length the machine maybe set to produce.

EDWARD P. SPAINE.

